Plastic casting machine



1| N 1% W W 5 ll 1 9% R E S m m mM Q\ Q QM I MwmMwM m w E mm W %4 0 1 If Q m w W II \N WV \M .nwb MNMNQV .0. &% QM x \K lIull Ifv E ATTORNY July 27, 1948. L. H. MORIN LASTIC CASTING MACHINE Filed April 25, 1944 Patented July 27, 1948 UNITED STATES PATENT, OFFICE PLASTIC CASTING MACHINE Louis H. Morin, Bronx, N. Y., a ssignor of one half to Davis Marinsky, Bronx, N. Y.

Application April 25, 1944, Serial No. 532,659

14 Claims.

This invention relates to machines for die casting or forming plastic materials, and particularly in the production of continuous elongated plastic members. More particularly, the invention relates to machines of the kind def ned employed for forming spiral or helix members longitudinally of a conductor in producing Fig. 2 is a detail view looking in the direction,

of the arrows 2-2 of Fig. 1, showing only a part of the construction.

Fig. 3 is a view similar to Fig. 1, showing only a part of the construction and showing a modification; and

Fig. 4 is a face view of a part of the construction shown in Fig. 1.

In machinesfor die casting plastic materials, particularly the various kinds of thermoplastic materials, it has been the common practice to form a casting in the die cavity or impression, then to separate the dies and remove the resulting icasting therefrom. Inthe machine forming the subject matter of this application, a. differentmethod of procedure is followed, namely, a successive series of castings are formed in the cavity or impression of the die, each casting be-,

ing formed directly upon the preceding casting,

thus resulting in the formation of a continuous elongated cast member, such for example, as a spiral or helix arranged upon an electric conductor. In other words, it may be said that a casting machine. is provided wherein an elongated spiral or helix member is formedby a successive series of intermittent casting operations. In other adaptations of the inventiomthe spiral or helix member may include at spaced intervals rings or bands encircling the conductor, the latter being formed bythe use of supplemental die members which are movable relatively to one surface of the primary die. 7

The casting machine diagrammatically illustrated in the accompanying drawing, from the standpoint, of the feedof the plastic material and operation of the plunger is substantially-the same as the structures disclosed in prior Patents i 2 a 2,244,425, June 3, i941, and 2,272,220, February In Fig. 1, It! represents the. hopper for the ception' of powdered or granular plastic mate.-

rial. At the bottom of the hopper-is slide'lll having a measuringaperture I2 therein which" measures the quantity of plastic material deliv-r ered in each stroke to the discharge chute, I3: which is arranged over tlie funnel like member I4 arranged directly above the admission aperture l5 into the cylinder is. The slide ll hasa depending arm ll coupled with the outer end [8 of the tubular plunger, which plungeris actuated through the bell crank mechanism generally in; dicated by the reference, 19. It will thus be seen that in the forward stroke of the plunger, the slide ll isalso moved forwardly; a

The plastic material delivered into the funnel M in the forward stroke of the slide Il drops upon the forward. reduced end 20 of the tubular.

plunger and in the retracted movement of, the plunger, to the position shown in Fig. 1 of the drawing, this material then drops into the cyle inder in position to be advanced in the next in jection stroke. The quantity admitted into the,

cylinder is su fficient to form at least asing le casting. V I

At 2| is diagrammatically illustrated theh eat ing coil at the discharge, end of the cylinder, l6 for heating the plastic ,materialjin the cylinder, and this coil is automatically controlled to reg:

. ulate the required temperature, as is known. in,

this art. Arranged at the discharge end ofthe cylinder is a die 22, the die being mounted, in theoffset portion 23 of a1 die holder. 24, ,this holder having a flangeportion 25 adapted to bear against a hair thrust bearing 26 supported, between suitable plates 21 and 28. The purpose of this construction is toprovide free rotation of the holder 24 as well as the die22 mounted therein. To simplify theconstruction, oi the die 22, it may be composed of separate .parts each part being secured to the holder 24 by screws: 29. The die 22 has formed therein an impression or cavity illfashioned to receive a conductor 3l, and to form around theconductor .a portion of a continuous spiral or helix member, as more fully hereinafter set forth. The length of the spiral or helix in the die 20 is substantially equal to what might be considered a complete turn. M

It will, of course, be understood thatthedie holder will be water cooled, as in conventional suitable pawl and lever mechanism 39 is employed to intermittently rotate the shaft 31 a quarter revolution which in turn will rotate the shaft 34 one complete revolution.

Supported in connection with the end of the shaft 34 adjacent the die 22 are radially movable jaw members 40 which are adapted to engage and grip the conductor 3| in the intermittent feed of the conductor, as later described. Springs 4| are employed to normally support the roller ends 42 of the jaw members in engagement with a conical or cup shaped sleeve 43 which is slidably mounted on the shaft 34. The sleeve 43'has a grooved end portion 44 adapted to be engaged by a yoke shaped lever 45 suitably operated in the machine to move the sleeve 43 to the right in moving the jaws 40 into their gripping position, as will be apparent.

The shaft 34 is supported in a slide 463, mounted to move back and forth in the machine with respect to the die 22, a suitable link 4? being coupled with operating mechanisms of the machine in performing this operation timely with the operation-of the plunger 18.

' In Fig. 3 of the drawing is shown a slight modification. In this figure, 48 represents a die which differs from the die 22 simply in having an annular recess 49 in the outer surface thereof, which recess is interrupted solely by the passages 50 in the die which form the helix or spiral 5! on the conductor 52. .The helix or spiral differs from the helix or spiral 33 in that it includes at spaced intervals the collars or sleeve portions 53 which are partially formed by the recess 49. The remainder of the collars are formed by the recess'or cavity 54 in two supplemental die members 55 and 56, which are movable toward and from the conductor 52 over the outer surface of the die 48. These supplemental dies 55 and 55 will also include cavit portions conforming with the spiral or helix 5|, as will clearly appear from a consideration of Fig. 3 of the drawing. At 51 is shown the discharge end of a cylinder similar to the cylinder I6.

To rotate the die holder 24, a tubular pinion 58 is arranged upon and secured to the outer surface of the holder 24. The gear 59 meshes with the pinion 58, the gear being arranged on a shaft 60, intermittently rotated through a ratchet wheel 6! similar to the wheel 38 and the pawl and lever'mechanis'm 62, the latter being shown in detail in Fig. 4, a view looking in the direction of the arrows 4-4. This construction provides positive rotation of the die holder in the operation of'feeding the wire 3! through the die 22 and in-injecting plastic material into the die. With the construction shown in Fig. 3 of the drawing, the die holder will be rotated in a manner illustrated in the companion application SerialNo. 532,660, filed April 25, 1944.

The operation of the machine will be readily understood from the foregoing description when taken in connection with the accompanying:

drawing and the following statement.

Let us assume that in the full line illustration of Fig. 1, particularly with respect to the gripper mechanism, the machine has just completed the 4 formation of a cast section of the spiral or helix 33 in the die 22. The sleeve 43 is then moved to the left to release the jaws 40, which are then moved outwardly by the springs 41, this movement is slight and sufficient to disengage the conductor 3!. The slide 45 together with the sleeve 43 are then moved to the right, and during this operation, the shaft 34 is rotated to move the jaws around the spiral or helix 33. During this operation, the plunger l8 has been moved to the right, assuming the truded sections.

position similar to that shown in Fig. 1 of the drawing, after which the powdered or granular plastic material which had previously been deposited in the funnel l4 will drop into the cylinder it in front of the nd 2!] of the plunger. During the above operation, the cast section or unit of the spiral or helix 33 remains stationary in the die 22. i

The machine is now' ready for the next opera-'- tion which can be regarded as the casting or'in jecting operation. The sleeve 43 is now moved to the right on the shaft 34 to force the jaws 4ll inwardly into firm gripping engagement with the conductor 3i. advanced to move the powdered or granular plastic material to the left in the cylinder 16 to a point where injection of the heated plastic material at the-outer end of the cylinder is to begin. At this moment, the slide 46 is moved to the left, the jaws being firmly supported in the sleeve 43 in this operation. This operation feeds the conductor 3! including the pre-cast section of the spiral or helix insulator 33 to the left and out of the die 22, the die holder 24' being positively rotated in this operation by the intermittent rotating means employed and simultaneously another cast unit or section of the spiral or helixinsulator is formed on the conductor as the plunger I8 is moving forwardly simultaneously with the movement of the slide 46.- At the completion of this last operation, the parts will again return substantially to the position shown in Fig. 1, excepting that in Fig. 1, the plunger has been shown in its retracted position, it being understood that pressure is relieved from the casting material immediately upon formation of the cast section as described above.

It will be understood that the above describedcycle of operation is automatic and repeated at intervals to form the successive cast sections or portions of the insulator, and the speed of this operation will depend largely upon the amount of material in each unit cast section. However, each unit will be permanentl united with the adjacent unit so as to form a continuous elongated spiral or helix insulator on the conductor. In otherwords, it will be apparent that the cavity 3llo'f the die is always exposed to the outer nozzle discharge end of the cylinder I5, and in this sense, the cast insulator 33 maybe said to be formed from 'a' plurality of intermittently ex- The operation of the structure shown in Fig. 3 will be the same as that shown in Fig. 1, with the exception that at the beginningof the casting'operation the dies and 56 will be separated to allow for the feed of the workpiece to the left and substantially at the completion of the injection stroke the dies 55 and 56 will be quickly moved into engagement with the conductor52 and in the final stroke of the plunger casting material will be forced into the cavity recesses 49 and 54 in forming the ring like or sleeve like members 53 which completely encircle the con- The plunger 18 willnow be ducton 52; Itwill be apparent that the die 48 or the holder therefor will be intermittently rotated by: means similar to thatshown inFig; 1, except that thei gear such as 59' williengage a gear face onthe flange portion 25,as is disclosed in the companion applicatio'n referred to.

From the foregoing, it will be apparent that thefe'edenmechanism drawsthe conductor 3| including the-insulator 33 thereon from right to left=ina series of intermittent feeds, each feed stroke being governed by the length of the cavity or-impression in'the die.- During this feed stroke, the=die is rotated tofeed the die around the precast insulator as the casting material is pressure injected into the die cavity so that when the die again comes at rest, thecavity will again be filled, and a new section of the insulator formed.

1. A machine-for forming helical die castings comprising a castingn'iechanism and a feed mechanism; the casting mechanism comprising a cylinder for receiving casting material and having a nozzle discharge end, a die abutting said n'oz'zle discharge end having a helically shaped cavity openingthrough opposed ends thereof, means supporting the die to maintain one end of' the cavity in constant registration with said cylinder, means for intermittently feeding casting material into the cylinder, a plunger in said cylinder movable toward said die for pressureinjectingcastingmaterial into the cavity of' said die, said casting mechanism having a passage extending ther'ethrough longitudinally of said cylinder for receiving a strand whereby a casting of helical contour may be cast'on the strand in said die; said feed mechanism being movable toward and from the die and having grippers which are themselves movable to engage said strand with the casting" thereon, said feed mechanism including said grippersserving to draw said strand and casting out o'f-said die.

2; A machine for forming helical die castings comprising a casting mechanism and a feed mechanism; the casting mechanism comprising a cylinder for receiving casting material and having a nozzle discharge end, adie abutting said nozzle discharge end having a helically shaped cavity opening through opposed ends thereof, means supporting the die to maintain one end of the cavity in constant registration with said cylinder, means for intermittently feeding casting'material into the" cylinder, a plunger in said cylinder movable toward said die for pressure cavity opening through opposed ends thereofir rotatable means supporting the die to maintaincne' end of the cavity in constant registration with said cylinder, means" for intermittently feeding casting material intothe cylinder; a plunger in said cylinder movable toward said-die for pres sure injecting casting material into the cavity-of said die. said plunger and die having a passage extending therethrough for receiving a cable whereby a casting of helical contour may be cast abo'utthe cable" in said'die; said feed mechanism" being movable toward and from the die andhav ing grippers movable to intermittently engagesaid cable with the'casting thereon, said feed mecha die during movement of said cable an'd casting therefrom! H 4. A machine for forming helical die castings comprising a casting mechanism and afeed mechanism; thecasting mechanism comprising a cylinder for receiving casting material" and:

injectingcasting material into the cavity of said 6 dieysaidplunger and die having a passageextending=therethrough for receiving a cable whereby a casting of-helical contour may be cast about the cable in said die; said feed mechanism being movable toward and from thedie and having grippers movable to intermittently engage said cable with the casting thereon, said feed mechanism including the grippers serving to intermittently move said cable and casting out of said die.

3. A machine for forming helical die castings comprising a casting mechanism and a feed mechanism; the casting mechanism comprising a cylinder for receiving casting material and havinga nozzle discharge end, adie abutting said nozzle discharge end having a helically shaped having a nozzle discharge end, a die abutting said nozzle discharge end having a helically shaped cavity openingthrough opposed-ends thereof, a second die comprising a pair of die members movable toward and from each other; said second die having a cavity registeringwith the cavity of said first named die, means sup:

porting said dies tomaintain one end of the cavity of said first named die in constant regis'-- tration with said cylinder, means for intermit tently fedding castingmaterial into" the cylinder,

a plunger in said cylinder movable towardsaid dies for pressure injecting casting material into the cavity of said dies, said casting mechanism having a passage extending therethrough longitudinally of said cylinder for receiving a'strand whereby a castingof helical contour may becast on the strand in said dies; said feedmechanism' being movable towardiand fronithe diesand hav=-- ingvlgripperswwhich are themselves movable "to engage said strand with the casting thereon, said feed mechanism including said grippers serving to draw said strand and casting out of saiddies':

5. A die casting machine comprising means for intermittently forming die castings one directly uponthe other in producing an elongated cast product, a feeder mechanism for intermittentlymoving the product in synchronism with the formation of successive cast portions of said product; said mechanism comprising jaw member's'movable toward and from the product, means for intermittently rotating said jaw members, and means for moving said jaw members longi tudinally of and with the product in successive intermittent feeds of the product through the machine.v

6. Adie' casting machine comprising means for' intermittently forming die castings one directly upon the other in producing an elongated cast product, a-feeder mechanism for intermittently moving the product in synchronism with the formation of successive cast portions of said product,said mechanism comprising jaw members movable toward and from the product, means for intermittentlymoving said jaw mem bers longitudinally of'and with the product in successive intermittent feeds of the product through the machine, andme'ans for'rotating' -th'e' jaw members during a movement thereof longitudinally of the product.

'7. A die casting machinecomprising means for intermittently forming die castings one directly upon the other in producing an elongated cast product, a feeder mechanism for intermittently moving the product in synchronism with the formation of successive cast portions of said product,said mechanism comprising jaw members movable toward and from the product, means for intermittently moving said jaw members longitudinally of and with the product in successive intermittent feeds of the product through the machine, means for rotating the jaw members during a movement thereof longitudinally of the product, and said first named means including a die, and a rotatable mounting for said die to provide rotation of the die in the operation of feeding the product therethrough.

' 8. Inadie casting machine for forming intermittent and united castings, a die having a cavity opening through opposed ends thereof, means maintained in constant engagement with one end' of the die cavity for intermittently injecting casting material into said cavity, and gripping means for intermittently gripping and withdrawing one cast part of a product from the cavity of the die through the other. open end of said cavity dur-' ing the operation of injecting casting material into said cavity to form the next cast part directly upon and united with the first mentioned cast part. i I

9. In a diecasting machine for forming intermittent and united castings, a rotatable die having a cavity opening through opposed ends thereof, means maintained in constant engagement with one end of the die cavity for intermittently injecting casting material into said cavity, means for withdrawing one cast part of a product from the cavity of the die through the other open end of said cavity during the operation of injecting casting material into said cavity to form the next cast part directly upon and united with the first mentioned cast part, and means for rotating the die during the operation of injecting casting material into the cavity'thereof.

10. In a die casting machine for forming intermittent and united castings, a die having a cavity opening through opposed ends thereof, means maintained in constant engagement with one end of the die cavity for intermittently injecting casting material into said cavity, mean's for withdrawing one cast part of a product from the cavity of the die through the other open end of said cavity during the operation of injecting casting material into said cavity to form the next castpart, rotatable mounting means for said die, and means for rotating said rotatable mounting means during the withdrawing of each cast product part from the cavity of the die.

11. In a die casting machine for forming intermittent'and united castings, a die having a cavity opening through opposed ends thereof, means maintained in' constant engagement with one end of the die cavity for intermittently injecting casting' material into said cavity, means for Withdrawing one cast part of a product from the cavity of the die through the other open'end of said cavity during the operation of injecting casting material into said cavity to form the next cast part directly upon and united with the first mentioned cast part, a pair of dies movable over one surface of the first named die, said pair of dies having cavities registering with the cavity of the first named die, and said pair of dies being movable toward and from each other in each cycle of successive casting operations of the machine.

- ,12.. A die casting machine for forming a casting in an elongated member comprising a rotat ably mounted die having a cavity opening through opposed surfaces of the die, meansat one side of ing casting material into the die cavity simultaneously with the feed of the member through the die cavity, and means for intermittently rotating.

said die during the feeding of said member through the cavity of the die.

13. In a die casting machine, the combination with a heated cylinder and means for-intermittently feeding castingmaterial into the cylinder and discharging the same from the discharge end thereof, of a die having a cavity therein opening through opposed surfaces of the die, rotatable supporting means for maintaining one of said surfaces of the die in constant engagement with the discharge'end-of said cylinder, one end of the cavity opening through said surface being thus:

maintained in constant registration with the discharge end of the'cylinder, means forintermittently rotating said rotatable supporting means during the operation of injecting casting material into the cavity of said die, and means for drawing a casting through the other open end of the cavity during the rotation of said rotatable supporting means.

14. In a die casting machine, the combination with a heated cylinder, means for feeding casting material into the cylinder andfor discharge ing the same therefrom, of a die having a cavity therein opening through opposed surfaces of the die, a pair of supplemental dies movable rela-.

tively to the first die and to each other and form-1 ing a cavity which is an extension to the cavity of the first die, rotatable supporting means for maintaining one of said die surfaces in constant engagement with the discharge end of said cylinder, one end of the cavity opening through said surface being thus maintained in constant regis-,

. REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 551,306 Converse et al. Dec. 10, 1895 724,287 Heilmann Mar. 31, 1903 1,577,336 Marsden -Mar. 16, 1926 1,706,728 Daniels Mar. 26, 1929 1,824,482 Hartmann Sept. 22, 1931 1,845,249 Derby Feb; 16, 1932 1,890,802 Apple Dec. 13, 1932 1,929,395 Barton Oct. 3,1933 2,127,857 Bond Aug. 23, 1938 2,226,043 Weaver Dec. 24, 1940 2,348,043 Taylor May2, 1944 FOREIGN PATENTS Number Country I Date 16,542 Great Britain July 18, 1942 401,428 Great Britain Nov. 16," 1933 445,852

' Great Britain Apr. 17, 1936" of the v 

